The space available on watch dials does not always make it possible to achieve displays in the best conditions for legibility, especially when the watch cases are small, and/or of non-circular shape. This difficulty is amplified where multiple complications are present in the movement, creating a conflict between the display areas.
Controlling a display member, particularly a hand, over a required trajectory, which is other than circular, often results in the use of milled cams, in a substantial thickness, and in a lack of versatility and difficulty in adapting the mechanism for a display with a different trajectory. Known articulated hand mechanisms do not permit easy adjustment of the orientation and reference elongation of the hands. These complications also require highly qualified operators.